Design by Team(Partnering)
Design by Team(Partnering) For ef?cient execution of systems design of a civil engineering project, a design organization superior to that used for traditional design is highly desirable. For systems design, the various specialists required should form a design team, to contribute their knowledge and skills in concert.
One reason why the specialists should work closely together is that in systems design the effects of each component on the performance of the whole project and the interaction of components must be taken into account. Another reason is that for cost-effectiveness, unnecessary components should be eliminated and, where possible, two or more components should be combined. When the components are the responsibility of different specialists, these tasks can be accomplished with ease only when the specialists are in direct and immediate communication.
In addition to the design consultants required for traditional design, the design team should be staffed with value engineers, cost estimators, construction experts, and building operators and users experienced in operation of the type of project to be constructed. Because of the diversity of skills present on such a team, it is highly probable that all rami?cations of a decision will be considered and chances formistakes and omissions will be small.
Project Peer Review The design team should make it standard practice to have the output of the various disciplines checked at the end of each design step and especially before incor- poration in the contract documents. Checking of the work of each discipline should be performed by a competent practitioner of that discipline other than the original designer and reviewed byprincipals and other senior professionals.
Checkers should seek to ensure that calculations, drawings, and speci?cations are free of errors, omissions, and con?icts between building components. For projects that are complicated, unique, or likely to have serious effects if failure should occur, the client or the design team may ?nd it advisable to request a peer review of critical elements of the project or of thewhole project. In such cases, the review should be conducted by professionals with expertise equal to or greater than that of the original designers; that is, by peers, and they should be independent of the design team,whether part of the same ?rm or an outside organization. The review should be paid for by the organization that requests it. The scope may include investigation of site conditions, applicable codes andgovernmental regulations, environmental impact, design assumptions, calculations, drawings, speci?cations, alternative designs, constructability, and conformance with the building program. The peers should not be considered competitors or replacements of the original designers and there should be a high level of respect and communication between both groups. A report of the results of the review should be submitted to the authorizing agency and the leader of the design team.
(For additional information on peer review contact the American Consulting Engineering Council, 1015 15th Street, N.W., Washington, DC 20005, website www.acec.org or the American Society of Civil Engineers, 1801 Alexander Bell Drive, Reston Virginia 20191-4400, www.asce.org).
Application of Systems Design Systems design may be used pro?tably in all phases of project design, but it is most advantageous in the early design stages. One system may be substituted for another, and components may be eliminated or combined in those stages with little or no cost.
In the contract documents phase, systems design preferably should be applied only to the details being worked out then. Major changes are likely to be costly. Value analysis, though, should be applied to the speci?cations and construction contract because such studies may achieve signi?cant cost savings. Systems design should be applied in the construction stage only when design is requiredbecause of changes necessary in plans and speci?cations at that time. The amount of time available during that stage, however,may not be suf?cient for thorough studies. Nevertheless, value analysis should be applied to the extent feasible.
1.10 Value Engineering
In systems design, the designers goal is to select an optimum, or best system that meets the needs of the owner or client. Before the designers start designing a system, however, they should question whether the requirements represent the clients actual needs. Can the criteria and standards affecting the design bemade less stringent? This is the ?rst step in applying value engineering to a project. After the criteria and standards have been reconsidered and approved or revised, the designers design one or more systems to satisfy the requirements and then select a system for value analysis. Next, the designers should question whether the system chosen provides the best value at the lowest cost. Value engineering is a useful procedure for answering this question and selecting a better alternative if the answer indicates this is desirable. Value engineering is the application of the scienti?c method to the study of values of systems. (The scienti?c method is described in Art. 1.9.)
The major objective of value engineering as applied to civil engineering projects is reduction of initial and life-cycle costs (Lloji. 1.6). Thus, value engineering has one of the objectives of systems design, which has the overall goal of production of an optimum, or best, project (not necessarily the lowest cost), and should be incorporated into the systems design procedure, as indicated in Art. 1.9.
Those who conduct or administer value studies are often called value engineers or value analysts. They generally are organized into an interdisciplinary team, headed by a team coordinator, for value studies for a speci?c project. Sometimes, however, an individual, such as an experienced contractor, performs value engineering services for the client for a fee or a percentage of savings achieved by the services.
Value Analysis Value is a measure of bene?ts anticipated from a system or from the contribution of a component to systemperformance. This measure must be capable of serving as a guidewhen choosing among alternatives in evaluations of system performance. Because in comparisons of systems generally only relative values need be considered, value takes into account both advantages and disadvantages, the former being considered positive and the latter negative. It is therefore possible in comparisons of systems that the value of a component of a system will be negative and subtract from the systems overall performance. System evaluations would be relatively easy if a monetary value could always be placed on performance; then bene?ts and costs could be compared directly. Value, however, often must be based on a subjective decision of the client. p.sh., how much extra is the client willing to pay for beauty, prestige, or better labor or community relations? Consequently, other nonmonetary values must be considered in value analysis. Such considerations require determination of the relative importance of the clients requirements and weighting values accordingly.
Value analysis is the part of the value engineering procedure devoted to investigation of the relationship between costs and values of components and systems and alternatives to these. The objective is to provide a rational guide for selection of the lowest-cost system that meets the clients actual needs.
Measurement Scales For the purpose of value analysis, it is essential that characteristics of a component or system on which a value is to be placed be distinguishable. An analyst should be able to assign different numbers, not necessarily monetary, to values that are different. These numbers may be ordinates of any one of the following four measurement scales: ratio, Interval, ordinal, nominal.
Ratio Scale This scale has the property that, if any characteristic of a system is assigned a value number k, any characteristic that is n times as large must be assigned a value number nk. Absence of the characteristic is assigned the value zero. This type of scale is commonly used in engineering, especially in cost comparisons. p.sh., if a value of $10,000 is assigned to system A and $5000 to system B, then A is said to cost twice as much as B.
Interval Scale n This scale has the property that equal intervals between assigned values
represent equal differences in the characteristic being measured. The scale zero is
assigned arbitrarily. The Celsius scale of temperature measurement is a good example of an interval scale. Zero is arbitrarily established at the temperature at which water freezes and does not indicate absence of heat. The boiling point of water is arbitrarily assigned the value of 100. The scale between 0 and 100 is then divided into 100 equal intervals called degrees (8C). Despite the arbitrariness of the selection of the zero point, the scale is useful in heat measurement. p.sh., changing the temperature of an object from 40 to
60 8C, an increase of 20 8C, requires twice as much heat as changing the temperature from 45 to 55 8C, an increase of 10 8C.
Ordinal Scale This scale has the property that the magnitude of a value number assigned to a characteristic indicates whether a system has more or less of the characteristic than another system has or is the samewith respect to that characteristic. p.sh., in a comparison of the privacy afforded by different types of partitions in a building,
each partition may be assigned a number that ranks it according to the degree of privacy it provides. Partitions with better privacy are given larger numbers. Ordinal scales are commonly used when values must be based an subjective judgments of nonquanti?able differences between systems.
Nominal Scale This scale has the property that the value numbers assigned to a characteristic of systems being compared merely indicate whether the systems differ in this characteristic. But no value can be assigned to the difference. This type of scale is often used to indicate the presence or absence of a characteristic or component. p.sh., the absence of means of access to maintenance equipment may be
represented by zero or a blank space, whereas the presence of such access may be denoted by 1 or x.
.
Weighting In practice, construction cost is only one factor, perhaps the only one with a
monetary value, of several factors that must be evaluated in a comparison of systems. In some cases, some of the systems other characteristics may be more important to the owner than cost. Under such circumstances, the comparison may be made by use of an ordinal scale for ranking each characteristic and then weighting the rankings according to the importance of the characteristic to the client. As an example of the use of this procedure, calculations for comparison of two partitions for a building are shown in Table 1.1. Alternative 1 is an all-metal partition; alternative 2 is made of glass and metal.
In Table 1.1 the ?rst column lists characteristics of concern in the comparison. The numbers in the second column indicate the relative importance to the client of each characteristic: 1 denotes lowest priority and 10 highest priority. These are weights.
In addition, each partition is ranked on an ordinal scale, with 10 as the highest value, in accordance with the degree to which it possesses each characteristic. These rankings are listed as relative values in Table 1.1. For construction cost, for instance, the metal partition
is assigned a relative value of 10 and the glass-metal partition a value of 8 because the metal partition costs a little less than the other one. In contrast, the glass-metal partition
is given a relative value of 8 for visibility because the upper portion is transparent, whereas the metal partition has a value of 0 because it is opaque.
To complete the comparison, the weight of each characteristic is multiplied by the relative value of the characteristic for each partition and entered in Table 1.1 as weighted value. For construction cost, p.sh., the weighted values are 8 x 10 = 80 for the metal partition and 8 x 8 = 64 for the glassmetal partition. The weighted values for each
partition are then added, yielding 360 for alternative 1 and 397 for alternative 2. Although this indicates that the glass-metal partition is better, it may not be the best for the money. To determine whether it is, theweighted value of each partition is divided by its cost. This yields 0.0300 for the metal partition and 0.0265 for the other. Thus, the metal partition appears to offer more value for the money and would be recommended.
The preceding calculation makes an important point: In a choice between alternative systems, only the differences between system values are signi?cant and need be compared. Suppose, p.sh., the economic effect of adding thermal insulation to a building is to be investigated. In a comparison, it is not necessary to compute the total cost of the building with and without the insulation. Generally, the value analystneed only subtract the added cost of insulation from the decrease in heating and cooling costs
resulting from addition of insulation. A net saving would encourage addition of insulation. Thus, a decision can be reached without the complex computation of total building cost.
Value Analysis Procedure For value analysis of a civil engineering project or one of its
subsystems, it is advisable that the client or a clients representative appoint an interdisciplinary team and a team coordinator with the assignment of either recommending the project or proposing a more economical alternative. The team coordinator sets the
studys goals and priorities and may appoint task groups to study parts of the system in
accordance with the priorities. The value analysts should follow a systematic, scienti?c procedure for accomplishing all the necessary tasks that comprise a value analysis. The procedure should provide: An expedient format for recording the study as it progresses
An assurance that consideration has been given to all information, some of which may havebeen overlooked in development of the proposed system A logical resolution of the analysis into components that can be planned, scheduled, budgeted, and appraised
The greatest cost reduction can be achieved by analysis of every component of the proposed project. This, however, is not generally practical because of the short time usually available for the study and the cost of the study increases with time. Hence, the study should concentrate on those project subsystems whose cost is a relatively high
percentage of the total cost because those com- ponents have good possibilities for substantial cost reduction.
During the initial phase of value analysis, the analysts should obtain a complete understanding of the project and its major systems by rigorously reviewing the program, or list of requirements, the proposed design, and all other pertinent information. They should also de?ne the functions, or purposes, of each component to be studied and
estimate the cost of accomplishing the functions. Thus, the analysts should perform a systems analysis, as indicated in Art. 1.3, answer thequestions listed in Art. 1.3 for the items to be studied, and estimate the items initial and life-
cycle costs.
In the second phase of value analysis, the analysts should question the cost-effectiveness of each component to be studied (see Art. 1.11). Also, by using imagination and creative techniques, they should generate several alternatives for accomplishing the required functions of the component. Then, in addition to answers to the questions in Art. 1.3, the analysts should obtain answers to the following questions:
Do the original design and each alternative meet performance requirements?
What does each cost installed and over the life cycle?
Will it be available when needed?Will skilled labor be available?
Can any component be eliminated?
What other components will be affected by adoption of an alternative? What will the resulting changes in the other components cost?Will there be a net saving in cost?
When investigating the elimination of a component, the analysts also should see if any part of it can be eliminated, if two or more parts can be combined into one, and if the number of different sizes and types of an element can be reduced. If costsmight be increased by use of a nonstandard or unavailable item, the analysts should consider substituting a more appropriate alternative. In addition, the simpli?cation of construction or installation of components and ease of maintenance and repair should be considered.
In the following phase of value analysis, the analysts should critically evaluate the
original design and alternatives. The ultimate goal should be recommendation of the original design or an alternative, whichever offers the greatest value and cost-savings potential. The analysts should also submit estimated costs for the original design and the alternatives. In the ?nal phase, the analysts should prepare and submit to the client or to the clients representative who appointed them a written report on the study and resulting recommendations and a workbook containing detailed backup information.
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